This invention generally relates to valves such as luer lock valves which are used primarily in the medical field, and more specifically relates to a slidable type of valve used primarily in the medical field.
Slidable valves presently exist for use in the medical field. Such valves provide that the valve is initially biased into a closed position, where fluid cannot flow through the valve, and one or more internal components of the valve are slidable within the valve to actuate the valve into an open position, where fluid can flow through the valve.
One type of medical valve is the subject of United States patent application Ser. No. 09/523,354, now U.S. Pat. No. 6,299,132 and is shown in FIGS. 1 and 2 of the present application. Specifically, FIG. 1 shows the valve 10 in the closed position (wherein fluid cannot flow through the valve), and FIG. 2 shows the valve 10 in the open position (wherein fluid can flow through the valve). The valve 10 includes a valve body 12, a valve poppet 14 with luer taper (with sealing member 16 thereon), an internal resilient valve stem 18, a metal compression spring 20 and a valve plug 22, all of which are within the flow path of fluid moving through the valve (the arrows 24 shown in FIG. 2 illustrate the fluid flow path (in one of two possible directions) through the valve 10). The valve stem 18 may include flutes or ribs on an external surface 26 thereof to facilitate fluid flow around the stem 18 when the valve 10 is in the open position.
In use, engagement or mating structure 28, such as a syringe, another valve or some other structure, engages the valve poppet 14, pushing it generally into the valve body 12 causing the valve 10 to move from the closed position as shown in FIG. 1 to the open position as shown in FIG. 2. As shown in FIG. 2, when the valve 10 is in the open position, the valve stem 18 is disengaged from a valve seat 30 in the valve 10. This provides that fluid can ultimately flow from a bore 32 provided in the valve poppet 14 to an area 34 adjacent the periphery of the valve stem 18, or vice versa if the fluid is flowing in the opposite direction.
In the case where the fluid flows from left-to-right in FIG. 2, fluid initially enters the bore 32 in the valve poppet 14 (i.e. from the mating structure 28), and travels to a notch 36 in the valve poppet 14 (and/or to a notch (not shown) in surface 38 of the valve stem 18). The valve stem 18 deflects the fluid to an area 34 adjacent the periphery of the valve stem 18, and the fluid flows along the external surface 26 of the valve stem 18 (and along the ribs, if provided, on the external surface 26 of the valve stem 18), past the valve seat 30, along the compression spring 20, and out the plug 22, and specifically between fins of the plug 22 and out the valve 10. In the opposite direction, fluid flows into the plug 22 of the valve 10, along the compression spring 20, past the valve seat 30, along the periphery of the valve stem 18 (and along the ribs, if provided, on the external surface 26 of the valve stem 18), to the notch 36 in the valve poppet 14 (and/or to a notch (not shown) in surface 38 of the valve stem 18), and through the bore 32 in the valve poppet 14 to the mating structure 28.
The overall design of the valve shown in FIGS. 1 and 2xe2x80x94being that there are so many components in the fluid flow pathxe2x80x94results in substantial restriction to fluid flow through the valve 10. As a result, the valve 10 cannot effectively conduct fluids having viscosities of 1.0 to 1.5 centipoise and above. Additionally, the design provides that there are numerous cavities or xe2x80x9cdead areasxe2x80x9d for entrapment of fluid within the valve 10. The existence of dead areas, and the fact that there so many components in the fluid flow path, creates turbulence in the fluid flow as the fluid flows through the valve 10. The turbulence renders the valve 10 a poor candidate for transmitting human blood, blood products, or any other material which is sensitive to turbulence. With regard to blood, concerns of lycing (i.e. damage to blood cells) and retention of clotted blood within the valve 10 gives rise to problems with possible infusion of thrombolotics or fibrous re-injection into a patient. The low viscosity conduction limits of the valve design shown in FIGS. 1 and 2 restrict its utilization for high viscosity materials, thus limiting broader employment of the valve in a clinical environment.
Furthermore, the design shown in FIGS. 1 and 2 provides that while the valve poppet 14 is installed through the one end 40 of the valve 10, the other components (i.e. the valve stem 18, compression spring 20, and plug 22) are installed through the other end 42. This complicates and increases the cost of the assembly process.
A general object of an embodiment of the present invention is to provide a valve which has increased flow rate and an unobstructed fluid flow path.
Another object of an embodiment of the present invention is to provide a valve which has fewer components within the fluid flow path.
Still another object of an embodiment of the present invention is to provide a valve which causes less turbulence to the fluid flow.
Still yet another object of an embodiment of the present invention is to provide a valve which minimizes the residual volume (i.e. xe2x80x9cdead areasxe2x80x9d) contributing to fluid entrapment.
Still yet another object of an embodiment of the present invention is to provide a method of assembling a valve wherein components are installed through one end of a valve body, but not the other.
Briefly, and in accordance with at least one of the foregoing objects, an embodiment of the present invention provides a valve that has at least one internal port which aligns with an internal slot to permit fluid flow. Specifically, the valve includes a valve body that has a sealing surface and at least one internal slot. A valve core is disposed in the valve body, and the valve core includes at least one port. Spring means is engaged with the valve body and valve core, and the spring means biases the valve core into a closed position wherein the port of the valve core is aligned with the sealing surface of the valve body thereby prohibiting fluid flow through the valve. The valve core is slidable within the valve body such that the valve is actuated into an open position wherein the port of the valve core becomes aligned with the internal slot of the valve body thereby allowing fluid flow through the valve. Preferably, at least one end of the valve is configured for a luer lock fitting.
A bore extends through the valve core, along a longitudinal axis thereof, and the bore defines a fluid flow area. The one or more ports on the valve core which align with the sealing surface of the valve body when the valve is in the closed position and with the one or more slots in the valve body when the valve is in the open position consists of one or more openings in a wall of the valve core. The valve body also includes a fluid flow area. Hence, a fluid flow path through the valve is defined by the fluid flow area defined through the valve core (i.e. the bore and the one or more ports) and the fluid flow area of the valve body. The spring means is generally between the valve body and valve core, but is not within the fluid flow path through the valve.
Preferably, each slot in the valve body is larger than each respective port of the valve core, and each port of the valve core is larger than a cross-sectional diameter of the bore which extends through the valve core. Preferably, the valve core includes two ports and the valve body includes two corresponding slots which align with each other when the valve core slides within the valve body to the open position. The ports of the valve core and the slots of the valve body are preferably 180 degrees apart relative to each other.
Preferably, a first sealing member and a second sealing member are disposed on the valve core, where the first sealing member engages the sealing surface of the valve body whether the valve core is in the open or the closed position, and the second sealing member engages with the sealing surface of the valve body when the valve core is in the closed position, but disengages from the sealing surface of the valve body when the valve core is in the open position. The valve core may include at least one barb which abuts against an internal surface of the valve body when the valve core is biased into the closed position by the spring means. Preferably, the valve body includes a pocket, the valve core includes a shoulder, and the spring means is disposed in the pocket of the valve body and engages the shoulder of the valve core. Again, preferably the spring means is generally between the valve body and valve core, but is not within the fluid flow path through the valve. As an alternative to the sealing members, a resilient material may be over-molded or co-injected on the valve core to enhance the seal with the structure which is engaged with the valve and to enhance the seal between the valve core and valve body.
Another embodiment of the present invention provides a valve that includes a self-aligning valve seat carrier which is pivotably or adjustably engaged with a valve core member. Specifically, the valve includes a valve body which includes a sealing surface, and the valve core is disposed in the valve body. The self-aligning valve seat carrier also includes a sealing surface. Spring means is engaged with the valve body and the valve core, and the spring means biases the valve core into a closed position wherein the sealing surface of the self-aligning valve seat carrier engages the sealing surface of the valve body thereby prohibiting fluid flow through the valve. The valve core is slidable within the valve body such that the valve is actuated to an open position wherein the sealing surface of the self-aligning valve seat carrier disengages from the sealing surface of the valve body thereby allowing fluid flow through the valve.
The self-aligning valve seat carrier may take several different configurations. For example, the self-aligning valve seat carrier may include a pair of arms which engage corresponding recessed grooves proximate the end of the valve core, may include a ball which engages a corresponding socket on the valve core, or may include a barb which engages corresponding structure on an end of the valve core. A sealing member may be disposed on the valve seat carrier, or a sealing material may be co-injected or over-molded onto the exterior surface thereof.
Another aspect of the present invention provides a method of assembling a valve. The method includes installing a plurality of components through one end of a valve body, and installing no components through an opposite end of the valve body. Hence, the assembly process is simplified and less costly.